Chemical Mechanical Polishing/Planarization (CMP) is a technique widely employed in semiconductor manufacturing for planarizing a first layer (or a first layer stack) down to a second layer (or a second layer stack). In the case of structures with wide dimensions such as large metal pads, wide trenches, etc. dishing of the first layer (or first layer stack) occurs in such large structures. For example, an oxide CMP process with high selectivity of oxide to nitride may cause oxide dishing while over-polishing the oxide to form an STI (shallow trench isolation) or LOCOS (LOCal Oxidation of Silicon) structure. Dishing occurs when more material is removed from the center of the structure being planarized, and the cross-section view has the profile of a dish and thus a nonuniform thickness. It is desirable to minimize or at least reduce dishing when planarizing structures with wide dimensions.